Swiveled and tilting chair.



0. 0. KRABOL.

SWIVELED AND TILTING CHAIR.

' I APPLICATION FILED APR. I. l9l8 Lz mm.

Patented Mar. 18, 1919.

2 SHEETSSHEET l- Ira/en or UZaus QAQ'QZQZ 0. 0. KRABOL.

SWIVELED AND TILTING CHAIR.

APPLICATION FILED APR. 1. I918.

Patented Mar. 18, 1919.

2 SHEETS-SHEET 2- llllllllllllllllllllll Inventbr OLAUS O. KBABOL, OF CHICAGO, ILLINOIS.

" 2 i SWIVEIJED AND TILTING CHAIR.

Specification of Letters Patent.

Patented Mar. 18, 1919.

Application filed April 1, 1918. Serial No. 226,035.

To all whom it may concern:

Be it known that I, OLAUS O. KRABoL, a

I citizen of the United States, and resident of by screws 29, or the like.

Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Swiveled and Tilting Chairs, of which the following is a specification, and which are illustrated in the accompanying drawings, forming a part. thereof.

The invention relates to chairs, and more particularly office chairs of the revolving and tilting type.

The object of the invention is to provide a chair of this type having superior strength, greater simplicity of construction, and being capable of ready adjustability.

In the drawings Figure 1 is a side elevation, partly in section, of a portion of a chair embodying the features of the present invention,

Fig. 2 is a perspective view of one of the parts of the chair;

Fig. 3 is a sectionon'the plane 33 of Fig. 1; I

Fig. 4 is a section on the plane 44 of Fig. 3;

Fig. 5 is a section on the plane 5-5 of Fig. 1; and

Fig. 6 is a perspective view, with parts broken away, of one of the improved chairs. In the drawings an entire chair has not been shown since the improvements constituting the invention relate to the means for connecting the seat to the legs, and not to the seat or the legs themselves. As is usual in chairs of the type illustrated, the legs, as 20, are secured to a centrally arranged block 21 which may suitably consist of a metallic casting. Centrally arranged in this casting is an aperture 22 for the reception of the screw 23 by which the heightof the seat 11 may be adjusted in well known manner.

The upper ends 24 of the legs butt against the sides of the casting 21, which is provided with tongues 25 adapted to enter corresponding grooves 26 in the ends of the legs to prevent lateral movement of the latter relatively to the casting. The ends 24 of the legs may be conveniently held against vertical movement by means of a flange 27,

integrally formed on the casting 21 on the upper side, and on'the lower side by means of a plate 28. The flange 27 and plate 28 may be secured to the ends 24 of the legs The weight of the chair and occupant tend to draw the lower parts of the ends 24 of the legs away from the casting, and while such movement may be restrained by means of the screws 29, additional retaining means are advisable.

A convenient form of retaining means is readily provided if the ends of the arms 30 of the plate 28 are struck up to form projections 31 which enter corresponding recesses in the under side of the legs. The inner walls of these recesses form shoulders which bear against the projections 31.

For improving the appearance of the chair filler blocks 9 may be provided, as shown more particularly in Figs. 3 and 4. These blocks are formed with a segmental outer,

surface concentric with the casting. Various means may be employed for retaining these blocks in position, a convenient method being to form the flange 27 with a downwardly projecting peripheral flange 32, and the plate 28 with segmental upstanding flanges 33 which engage the filler blocks, as illustrated in Fig. 4.

On the upper part of the casting is rotatably mounted a nut 34, by which the position of the screw 23 relatively to the casting 21 may be adjusted. A swivel connection is provided between the nut and the casting to allow the seat to be rotated without changing the position of the nut relatively to the screw, and thereby the height of the seat. For this purpose a' downwardly projecting annular flange 35 is provided which surrounds an annular projection 36 on the upper end of the casting, having an an? nular groove 37 into which projects the end of a set-screw 38, mounted on the flange 35. The nut 34 is normally prevented from rotating about the screw 23 by means of a pin 39, carried by the nut and entering a longitudinal slot 40 in the screw.

When it is desired to adjust the height of the chair this pin 39 'is withdrawn by pulling on its head 41 against the action of the spring 41 coiled about its shaft. The head of the pin is elongated and fits within a slot in the nut. By giving the pin a half turn after retraction it will be held in that position so that the nut may be freely rotated to the desired extent.

On the upper end of the screw 23 is fixed a bracket, as 42, to which a spider, as 10, connected to the under side of the seat 11, may be pivotally connected by suitable means, as a pin 15, to allow the seat to tilt in well known manner. The spider 10 may be conveniently formed of two angle bars, as 12,

bent outwardly toward their ends to provide a broad base for the chair. these angle bars, and secured thereto by rivets 13, or the like, is arranged a spreader the structure, forms a wall having functions hereinafter pointed out. The side portions 44 of this yoke carry the pivot pin 15 about which the seat tilts. The bracket 42 is formed with laterally extending lugs 43, through which the pin 15 passes, and the outer faces of which engage the side portions 44 of the yoke 14 to prevent lateral movement between the parts.

Within the yoke 14 a second yoke 45, of similar cross-section in a horizontal plane integral with the bracket 42, extends upwardly from the lugs 43. These yokes 14 and 45 are formed with registering apertures 46 and 47, respectively, through which passes a bolt 48. Around this bolt is arranged a helical spring 49, having one end in engagement with a block 50 fixed at the end of the bolt 48, and the other end in engagement with a non-rotatable block 51 slidably mounted on the bolt and seated against the bow of the yoke 14, which forms a limiting stop to prevent the chair seat from tilting forward.

- The tension of the spring 49 may be increased by drawing the bolt forward through the yokes 14 and 45, and for this purpose a hand wheel 54 is provided having a hollow internally threaded shank 55 for engagement with the thread on the end of the bolt. The shank 55 bears against a thrust block '52, having laterally extending portions with V-shaped notches on their under side for engagement with similarly formed projections 53 on the yoke 45, which allow the block 52 to rock thereon. The rotation of the bolt is prevented by the engagement of the spring with the blocks 50, 51.

As the seat is tilted backward the spring is compressed by the rearward movement of the yoke 14 away from the yoke 45. As a result of this movement the angular relation between the bolt 48 and the yoke 45 changes, and the thrust block rocks on its supporting projections 53 to a corresponding extent. Rearward movement of the seat may be limited by forming on the yoke 14 instanding lugs 60, and on the yoke 45 outstanding lugs 61 projecting into the paths of the lugs 60. These lugs are preferably arranged as far from the pivot pin 15 as possible to re duce the strain thereon, and for this purpose they are conveniently located substantially vertically above the pin 15.

By the described construction simplicity .fore been commonly used in the art. stresses'are so applied and limiting stops so Between.

and great strength ar'sciird. The spider and its appurtenances are built up of a much smaller number of parts than have her lei toplaced that the structure may be light while possessing the necessary strength, and the stability of the. chair is insured.

I claim as my invention- 1. In a support for a swiveled chair, in combination, a vertically apertured block having an upstanding annularly channeled flange, a threaded rod journaled Within the block aperture and having a longitudinal channel, a nut threaded upon therod and having a stud engaged with the flange channel, and a retractable element carried by the nut and engageable with the rod channel.

2. A cha1r comprising, in combination, a

seat, a support therefor including a centrally arranged casting, a plurality of legs having end portions abutting against the casting, means formed integrally with the casting for preventing the latter moving downward relatively to the said end portions, a plate arranged below the end portions, integral projections on said plate in engagement with shoulders on said end portions whereby the latter are prevented from moving away from the casting, and means independent of said projections for securing said plate to said end portions.

3. A plate for use with revolving chairs comprising a plurality of symmetricallydisiposed arms adapted to be secured to the legs of the chair, integral projections on said arms adapted to engage shoulders on the legs, and segmental upstanding flanges be tween the arms formed concentrically with the plate adapted to engage filler blocks between the leg 4. In a tilting chair, in combination, a suitable support having an integral upstanding yoke, a spider for attachment to the chair seat comprising a pair of spaced arms, a yoke depending from the spider and pivoted to the support, the bow of the yoke making contact with the first-named, yoke to limit forward movement of the chair bottom, and a spring device reacting against the rear wall of the second-named yoke.

5. A tilting chair comprising a'seat, a spider beneath the seat and connected there to including a central portion of U-shaped horizontal section, a support including a yoke of U-shaped cross-section in a horizontal plane arranged within said central portion, a pivotal connection between the said central portion and the yoke, and a spring device for yieldingly resisting separationof said central portion and yoke.

6. A tilting chair comprising a ,seat, a spider beneath the seat including a s reader of U-shaped horizontal section and ars secured to the uppermargins of the, side portions of the spreader, the bars being provided with means for attachment to the seat, a support including a yoke of U-shaped cross-section in a horizontal plane arranged within the spreader, a pivotal connection between the spreader and the yoke, and a spring device for yieldingly resisting separation of the spreader and yoke.

7. A tilting chair comprising a seat, a spider beneath the seat and connected thereto including a central portion of U-shaped horizontal section having its arms directed fonwardly, a support including a yoke of U- shaped cross-section in horizontal plane arranged between the arms of said central portion with its arms also projecting forwardly, a pivotal connection between the arms of the said central portion and the arms of the yoke Copies of this patent may be obtained for five cents each, by addressing the adjacent their lower margins, a spring bear- 1ng at one end agalnst the rear of said central portion, and means for operatively connecting the other end of the spring to the yoke .whereby separation of said central portion and the yoke is yieldingly resisted.

8. In a chair, in combination, a support having an upstanding projection U-shaped in horizontal section, a spider having a depending spreader U-shaped in horizontal section and inclosing the projection, pivotal connection between the spreader and support, and stop lugs projecting inwardly from the depending side walls of the spreader for engaging the forward margins of the projection.

OLAUS o. KRABOL Commissioner of Patents.

Washington, D. 0. 

